Moto Rim Size

Hi all i have got a vector frame (Typhoon) DNM USD-8 SA forks and Burner 2 rear shock.

What size moto rim do you think would be best for me I'm 5.6?
I was thinking of this https://www.ebay.co.uk/itm/142669134839
or is a 16" rim going to be too small?

The bike I have at the moment the seat height is 35" and that is almost a perfect fit for me

There is little reason to use any moto rim sizes other than 21" on a bike that can fit fat MTB tires, unless you have a hub motor that needs to turn faster in a smaller wheel. 21" MX wheels have better rollover characteristics and are lighter than most smaller diameter moto wheels.

Ride height can be adjusted by other means than wheel diameter.